Automatic dynamic signal range control - has feedback from two RC circuits with short and long time constants to eliminate overshoot

摘要

The automatic signal range control circuit eliminates the overshoot effect which is usual with sudden amplitude surges. It achieves this by having two delay RC-networks with different time constants in parallel feeding an FET control element with clamping diodes controlling the feedback levels. Preceding the signal amplifier (4) and following a band pass filter (2) is the resistor/FET (7,8) regulator which is controlled by feed back signals from peak rectifiers (18,19) charging a capacitor (17) and from a second pair of rectifiers (10,11) charging a capacitor with a much longer time constant (12,13), whilst a resistor (22) in parallel to the first capacitor allows it to discharge.